{"id":3295,"date":"2026-04-09T10:22:02","date_gmt":"2026-04-09T08:22:02","guid":{"rendered":"https:\/\/silentdynamics.de\/?p=3295"},"modified":"2026-05-13T09:18:48","modified_gmt":"2026-05-13T07:18:48","slug":"seegangsverhalten","status":"publish","type":"post","link":"https:\/\/silentdynamics.de\/en\/2026\/04\/09\/seegangsverhalten\/","title":{"rendered":"Behavior in the Open Sea: Methods, Tools, and Key Performance Indicators"},"content":{"rendered":"<p>The <strong>Seaway Calculation<\/strong> is a central element of ship design and forms the basis for assessing the behavior of ships and floating structures in real sea conditions. It provides crucial information for safety assessment and operational planning.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">What is seaway analysis and why is it important?<\/h2>\n\n\n\n<p>Seakeeping refers to the dynamic forces generated by wind, waves, and currents to which a ship is exposed at sea. A well-founded seakeeping analysis allows for precise prediction of a ship's motion behavior as early as the design phase \u2013 before the keel is laid. This minimizes costly post-construction corrections and increases onboard safety.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Potential codes as the basis for seaway calculation<\/h2>\n\n\n\n<p>The analysis of wave calculations is usually done using <strong>Potential Codes<\/strong> performed. This method is based on potential flow theory and allows for a fast, numerically stable calculation of the hydrodynamic forces acting on a ship hull. Potential codes assume an incompressible, inviscid, and irrotational flow \u2013 assumptions that are well justified for seakeeping calculations in many practical cases.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Response Amplitude Operators (RAOs): The Heart of Motion Analysis<\/h2>\n\n\n\n<p>The core of wave state calculation is determining the <strong>Response Amplitude Operators (RAOs)<\/strong> \u2013 also called transfer functions \u2013 for all six degrees of freedom of the ship:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Surge<\/strong> Longitudinal movement<\/li>\n\n\n\n<li><strong>Sway<\/strong> Wobble movement<\/li>\n\n\n\n<li><strong>Heave<\/strong> \u2013 Hub movement<\/li>\n\n\n\n<li><strong>Roll<\/strong> Rolling motion<\/li>\n\n\n\n<li><strong>Pitch<\/strong> Tamping motion<\/li>\n\n\n\n<li><strong>Yaw<\/strong> \u2013 Gear movement<\/li>\n<\/ul>\n\n\n\n<p>RAOs describe how strongly a ship reacts to a wave of a specific frequency and direction. They are frequency-dependent and are determined for different ship speeds and wave heading angles.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Derived parameters: Accelerations, velocities, and seasickness criteria<\/h2>\n\n\n\n<p>From these RAOs, a variety of practice-relevant characteristic values are subsequently calculated at arbitrary locations on the ship:<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>Accelerations<\/strong> (e.g., at workplaces, crane locations, or load securing points)<\/li>\n\n\n\n<li><strong>Speeds<\/strong> ship motion in various sea state scenarios<\/li>\n\n\n\n<li><strong>Frequency criteria for seasickness<\/strong> Motion Sickness Incidence, MSI<\/li>\n\n\n\n<li><strong>Relative Movements and Freeboard<\/strong> for evaluating green water events<\/li>\n\n\n\n<li><strong>Operability indices<\/strong> for safe use under specific sea state conditions<\/li>\n<\/ul>\n\n\n\n<p>These results directly feed into ship design, equipment layout, and the planning of offshore operations.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Simulation with Open-Source Tools: PDStrip and NEMOH<\/h2>\n\n\n\n<p>The simulations are being conducted with the proven <strong>Open-Source Tools PDStrip<\/strong> or <strong>NEMOH<\/strong> performed<\/p>\n\n\n\n<ul class=\"wp-block-list\">\n<li><strong>PDStrip<\/strong> is a 2D strip theory code that is particularly well-suited for slender ship hulls and is characterized by high computational speed. It is ideal for initial design iterations and parametric studies.<\/li>\n\n\n\n<li><strong>NEMOH<\/strong> is a 3D potential flow panel code based on the Boundary Element Method (BEM). It is particularly well-suited for complex geometries, floating offshore structures, and cases where 3D effects cannot be neglected.<\/li>\n<\/ul>\n\n\n\n<p>Both tools are established in the scientific and engineering communities and benefit from active further development by research institutions worldwide.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Seamless integration into ship resistance analysis<\/h2>\n\n\n\n<p>A key advantage of our approach: the required input for wave calculation is <strong>fully compatible with the input for our ship resistance analysis<\/strong>. This means that geometry data and vessel parameters, once processed, can be directly used for both analysis types. This significantly reduces effort and ensures a consistent data foundation throughout the entire design process.<\/p>\n\n\n\n<h2 class=\"wp-block-heading\">Conclusion: Professional sea state calculation for safer and more efficient ships<\/h2>\n\n\n\n<p>Precise seakeeping analysis is essential for modern ship design. Using potential flow codes, RAO-based motion analysis, and powerful open-source tools like PDStrip and NEMOH, well-founded statements about a ship's seakeeping behavior can be made early in the design process. The close integration with resistance analysis makes our workflow particularly efficient.<\/p>\n\n\n\n<p><em>Do you have questions about wave load calculation for your project? <a href=\"\/en\/kontakt\/\">Contact Us<\/a> \u2013 we are happy to advise you.<\/em><\/p>","protected":false},"excerpt":{"rendered":"<p>Die Seegangsberechnung ist ein zentrales Element des Schiffsentwurfs und bildet die Grundlage f\u00fcr die Bewertung des Verhaltens von Schiffen und schwimmenden Strukturen in realen Seebedingungen. Sie liefert entscheidende Informationen f\u00fcr Sicherheitsbewertung und Betriebsplanung. Was ist Seegangsanalyse und warum ist sie wichtig? Unter Seegang versteht man die durch Wind, Wellen und Str\u00f6mungen erzeugten dynamischen Kr\u00e4fte, denen [&hellip;]<\/p>\n","protected":false},"author":1,"featured_media":1490,"comment_status":"closed","ping_status":"","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[963],"tags":[],"class_list":["post-3295","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-hydrodynamik"],"_links":{"self":[{"href":"https:\/\/silentdynamics.de\/en\/wp-json\/wp\/v2\/posts\/3295","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/silentdynamics.de\/en\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/silentdynamics.de\/en\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/silentdynamics.de\/en\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/silentdynamics.de\/en\/wp-json\/wp\/v2\/comments?post=3295"}],"version-history":[{"count":3,"href":"https:\/\/silentdynamics.de\/en\/wp-json\/wp\/v2\/posts\/3295\/revisions"}],"predecessor-version":[{"id":3396,"href":"https:\/\/silentdynamics.de\/en\/wp-json\/wp\/v2\/posts\/3295\/revisions\/3396"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/silentdynamics.de\/en\/wp-json\/wp\/v2\/media\/1490"}],"wp:attachment":[{"href":"https:\/\/silentdynamics.de\/en\/wp-json\/wp\/v2\/media?parent=3295"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/silentdynamics.de\/en\/wp-json\/wp\/v2\/categories?post=3295"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/silentdynamics.de\/en\/wp-json\/wp\/v2\/tags?post=3295"}],"curies":[{"name":"WordPress","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}